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Diffstat (limited to 'src/cpu/kvm/perfevent.cc')
| -rw-r--r-- | src/cpu/kvm/perfevent.cc | 246 |
1 files changed, 246 insertions, 0 deletions
diff --git a/src/cpu/kvm/perfevent.cc b/src/cpu/kvm/perfevent.cc new file mode 100644 index 000000000..cd8b970e9 --- /dev/null +++ b/src/cpu/kvm/perfevent.cc @@ -0,0 +1,246 @@ +/* + * Copyright (c) 2012 ARM Limited + * All rights reserved + * + * The license below extends only to copyright in the software and shall + * not be construed as granting a license to any other intellectual + * property including but not limited to intellectual property relating + * to a hardware implementation of the functionality of the software + * licensed hereunder. You may use the software subject to the license + * terms below provided that you ensure that this notice is replicated + * unmodified and in its entirety in all distributions of the software, + * modified or unmodified, in source code or in binary form. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are + * met: redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer; + * redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution; + * neither the name of the copyright holders nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + * Authors: Andreas Sandberg + */ + +#include <sys/ioctl.h> +#include <sys/mman.h> +#include <sys/syscall.h> +#include <sys/types.h> +#include <fcntl.h> +#include <syscall.h> +#include <unistd.h> + +#include <cassert> +#include <cerrno> +#include <csignal> +#include <cstring> + +#include "base/misc.hh" +#include "perfevent.hh" + +PerfKvmCounterConfig::PerfKvmCounterConfig(uint32_t type, uint64_t config) +{ + memset(&attr, 0, sizeof(attr)); + + attr.size = PERF_ATTR_SIZE_VER0; + attr.type = type; + attr.config = config; +} + +PerfKvmCounterConfig::~PerfKvmCounterConfig() +{ +} + + +PerfKvmCounter::PerfKvmCounter(PerfKvmCounterConfig &config, pid_t tid) + : fd(-1), ringBuffer(NULL), pageSize(-1) +{ + attach(config, tid, -1); +} + +PerfKvmCounter::PerfKvmCounter(PerfKvmCounterConfig &config, + pid_t tid, const PerfKvmCounter &parent) + : fd(-1), ringBuffer(NULL), pageSize(-1) +{ + attach(config, tid, parent); +} + +PerfKvmCounter::PerfKvmCounter() + : fd(-1), ringBuffer(NULL), pageSize(-1) +{ +} + +PerfKvmCounter::~PerfKvmCounter() +{ + if (attached()) + detach(); +} + +void +PerfKvmCounter::detach() +{ + assert(attached()); + + if (munmap(ringBuffer, ringNumPages * pageSize) == -1) + warn("PerfKvmCounter: Failed to unmap ring buffer (%i)\n", + errno); + close(fd); + + fd = -1; + ringBuffer = NULL; +} + +void +PerfKvmCounter::start() +{ + if (ioctl(PERF_EVENT_IOC_ENABLE, PERF_IOC_FLAG_GROUP) == -1) + panic("KVM: Failed to enable performance counters (%i)\n", errno); +} + +void +PerfKvmCounter::stop() +{ + if (ioctl(PERF_EVENT_IOC_DISABLE, PERF_IOC_FLAG_GROUP) == -1) + panic("KVM: Failed to disable performance counters (%i)\n", errno); +} + +void +PerfKvmCounter::period(uint64_t period) +{ + if (ioctl(PERF_EVENT_IOC_PERIOD, &period) == -1) + panic("KVM: Failed to set period of performance counter (%i)\n", errno); +} + +void +PerfKvmCounter::refresh(int refresh) +{ + if (ioctl(PERF_EVENT_IOC_REFRESH, refresh) == -1) + panic("KVM: Failed to refresh performance counter (%i)\n", errno); +} + +uint64_t +PerfKvmCounter::read() const +{ + uint64_t value; + + read(&value, sizeof(uint64_t)); + return value; +} + +void +PerfKvmCounter::enableSignals(pid_t tid, int signal) +{ + struct f_owner_ex sigowner; + + sigowner.type = F_OWNER_TID; + sigowner.pid = tid; + + if (fcntl(F_SETOWN_EX, &sigowner) == -1 || + fcntl(F_SETSIG, signal) == -1 || + fcntl(F_SETFL, O_ASYNC) == -1) + panic("PerfKvmCounter: Failed to enable signals for counter (%i)\n", + errno); +} + +void +PerfKvmCounter::attach(PerfKvmCounterConfig &config, + pid_t tid, int group_fd) +{ + assert(!attached()); + + fd = syscall(__NR_perf_event_open, + &config.attr, tid, + -1, // CPU (-1 => Any CPU that the task happens to run on) + group_fd, + 0); // Flags + if (fd == -1) + panic("PerfKvmCounter::open failed (%i)\n", errno); + + mmapPerf(1); +} + +pid_t +PerfKvmCounter::gettid() +{ + return syscall(__NR_gettid); +} + +void +PerfKvmCounter::mmapPerf(int pages) +{ + assert(attached()); + assert(ringBuffer == NULL); + + if (pageSize == -1) { + pageSize = sysconf(_SC_PAGE_SIZE); + if (pageSize == -1) + panic("PerfKvmCounter: Failed to determine page size (%i)\n", + errno); + } + + ringNumPages = pages + 1; + ringBuffer = (struct perf_event_mmap_page *)mmap( + NULL, ringNumPages * 4096, + PROT_READ | PROT_WRITE, MAP_SHARED, + fd, 0); + if (ringBuffer == MAP_FAILED) + panic("PerfKvmCounter: MMAP failed (%i)\n", + errno); +} + +int +PerfKvmCounter::fcntl(int cmd, long p1) +{ + assert(attached()); + return ::fcntl(fd, cmd, p1); +} + +int +PerfKvmCounter::ioctl(int request, long p1) +{ + assert(attached()); + return ::ioctl(fd, request, p1); +} + +void +PerfKvmCounter::read(void *buf, size_t size) const +{ + char *_buf = (char *)buf; + size_t _size = size; + + assert(attached()); + + do { + ssize_t ret; + ret = ::read(fd, _buf, _size); + switch (ret) { + case -1: + if (errno != EAGAIN) + panic("PerfKvmCounter::read failed (%i)\n", errno); + break; + + case 0: + panic("PerfKvmCounter::read unexpected EOF.\n"); + + default: + _size -= ret; + _buf += ret; + break; + } + } while(_size); +} |